Scale



Oct. 12, 1937. G. G. MERCHEN SCALE Filed Jan. 22, 1937 5 Sheets-Sheet 1vINVENTOR.

/ew @THe/vien Uct. 12, 1937. G, MERCHEN 2,095,509

SCALE Filed Jan. 22,'1937 s sheets-sheet 2 IN VENTOR.

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ATTORNEY.

Oct. 12, 1937. G. G. MRCHEN SCALE Filed Jan. 22, 1937 3 Sheets-Sheet 3R. Y. wf n 1% A /f 6 8% fw Patented Oct. 12,1937

UNITED STATES PATENT OFFICE 2,095,509 I Scam Glen G. Mel-chen, Spokane,Wash.

Application January 22, 1937, Serial No. 121,796

s claim. (ci. 24a-z) This invention relates to a scale for weighing acontinuously moving stream of finely ground material such as flour,ground feed, insulation, cement, ores, and other ground materials.

One object of the invention is to provide a scale of such constructionthat the. ground material may be fed from a hopper onto a weighing'platform .adapted to support in a balanced condition a predeterminedweight of material and along which the material is moved at apredetermined rate of speed so that when the scale is in operation, .thequantity of material moved through the `scale along the weighingplatform thereof in a minute ory any other pre-v determined lengthof-time will be known in ad.- `vance and thus permit the total quantityof material which passes through the scale to beaccurately determined bynoting the length of time the scale has been in operation or by readingai counter in order to ascertain the number of revolutions made by thedrive shaft of an endless conveyor employed to move the material alongthe weighing platform of the scale. y

Another object of the invention is'to provide improved means forcontrolling flow of material from a hopper onto the weighing platform,the said means consisting of a gate for the hopper y and electricallyactuated means for moving the gate towards or away from a closedposition, and operation of the electrically actuated means beingcontrolled by movements of the weighing platform caused when the speedat which the material flows from the hopper varies. 4

Another object of the invention is to so construct the electricallyactuated means for `moving the gate of the hopDel.' that it will besufficiently sensitive to act promptly when the iiow of material varies,and toalso permit it to be actuated when flow of material eithervincreases Vor .de- 40 creases vfrom the normal rate of speed.

It isv another object of the invention to so construct the gateactuating means that it may be adjusted to control the neutral positionof the gate and thus allow the gate to be set in a position in which apredetermined quantity of material may ow from the hopper during apredetermined length of time when the vscale is adjusted to balance at acertain weight.

' Another object of the invention is to provide a scale ofthis'character in which the gate adjusting means is of a compact andsturdy con-- struction and not liable to get out of order when the scaleis in use.

The invention is illustrated in theaccompanying drawings. wherein Figure1 is a view showing the improved scale in side elevation.

Figure 2 is an enlarged view showing a portion ofthe scale 'in sideelevation. l

Figure 3 is a fragmentary sectional view taken vertically through thecam mechanism along the line 3-3 of Figure 1. Y

Figure 4 is a sectional view taken vertically through the rear drivealong the line 4-4 of Figure 1.

Figure 5 is a view partly in section and partially in elevation of theswitch controlling opening and closing of the hopper gate.

Figure 6 is a fragmentary sectional view of l the lower portion of thehopper and its gate.

' Figure '1 is a sectional view taken horizontally through the solenoidforming an element of the electrically actuated means for adjusting thehopper gate, the view being taken along the line 1-1 of Figure 1.

Figure 8 is a wiring diagram of the circuits for the electricallyactuated mechanism of the scale.

The scale constituting the subject-matter of this invention is of thetype .disclosed in my copending application, Serial No. 22,641, led May21, 1935, wherein the weighing platform and its connections with thescale beam have been illustrated in detail but a modified form of gateactuating means provided.

The base i ofthisscaleisintheformofan elongated housing formed of strongmetal and open at its bottom so that access may be had to the interiorthereof when assembling or when repairs or replacement of parts mountedtherein is necessary. Within 'the base or housing is mounted a weighingplatform 2 extending longitudinally therein between a receiving platformand a delivery platform I, which arrangement of parts is the same asdisclosed in the co-pending application referred to above. There hasalso been provided an endless `conveyor 4 for moving material from thereceiving platform along the weighing platform onto the deliveryplatform and from this delivery platform through the base or housing atone end thereof into a'suitable receptacle after it has been weighed. Ahopper I rises from the base at one end thereof over an inlet "formedthrough the top of the base and at one side the hopper carries asupporting arm t to which a scale beam 1 is pivotally mounted. A link 8.which extends vertically has its upper end pivoted to the inner end'ofthe scale beam l and its lower end pivoted to the rocker arm 9 of thescale mechanism which is pivoted, asshown at I0, and carries a crossbeam II upon which the weighing platform 2 rests. Pivoted vto thehousing is a yoke I2, as shown at I3, and the yoke in its turn ispivotally connected with the rear or inner end of the arm I4 whichextends through and is pivoted to the link 8, as shown at I5. When theweights I6 and I6 of the scale beam are set for a certain amount ofmaterial which may be 100 pounds or any amount desired, the scale willbe evenly balanced when 1 00 pounds of material is moving across theweighing platform and the arm I 4 will be substantially horizontal butthe quantity varies by material not flowing at the correct speed fromthe hopper onto the re'- ceiving platform for movement across theweighing platform by the endless conveyor 4 the dif-V ference in weightwill cause the arm I4 to swing vertically about its pivot I5 and a linkI1 con'- nected with .the outer or forward end of the arm will beshifted vertically either upwardly or' downwardly according to thedirection in which the arm rocks. The upper end portion of the link I1extends into a switch box I8 where it is pivoted to a rocker arm I9pivoted, as shown at 20, and at its upper end carrying horse-shoemagnets 2I and 22 which cooperate with glass yto mercury tube switches23 and 24 in a manner to be hereinafter set forth.

The ground material is delivered from a bin 25 or other 4source ofsupply into the hopper 5 and flows from the hopper through the outlet 26in the bottom thereof into the base and down upon the receivingplatform. The nely ground material has a tendency to pack in the hopperand in order to agitate the material and feed it towards the outlet,there has been provided an agitator 21 which is pivotally mounted torock about a horizontal axis, as shown at 28, and provided with a shank29 to which is pivoted a link or pitman bar 30. The pitman bar has itsother end pivoted'to a crank arm 3| carried by the shaft 32 of a motor33 and the motor shaft also carries a pulley 34 engaged by a belt whichis also trained about the pulley 36 carried by the shaft 31. The shaft31 is journaled through' the base and constitutes means for impartingmovefrom the hopper through the outlet must be controlled in order thata body of material weighing the predetermined amount iwill at all times'be moving across the weighing platform. In order to do so', there hasbeen provided a door or gate 38 which is arcuate to conform to thecontour of the hopper and slidably mounted for movementinto and out ofclosing relation tothe outlet. A rack 39 is xed to the gate adjacenteach end thereof and extends circumferentially of the annular wall ofthe hop'per and with ,each rack meshes a pinion 40 carried by a shaft4I. The shaft 4I is rotatably mounted through the base or casing I andhas-one end portion projecting from the casing, as shown in Figure 3. Tothis extended end portion of the shaft is fixed a gear or pinion 42which meshes with the teeth of an arcuate rack 43 formed across theupper end` of a quadrant 44 which is pivoted to a side wall of thecasing I, as shown at 45, and formed with an arcuate slot 46 throughVwhich the shaft 4I passes. A cam 41 which operates in an opening 48formed in the quadrant is keyed to the shaft 48 and when the shaft isturned this cam will be turned with the shaft eccentric thereto andcausethe quadrant to be swung'longitudinally of the base or casing I andimpart rotary motion to the shaft 4I so that the gate 39 will be movedtowards or away from a position to close the outlet opening of thehopper according to the direction in which the shaft is turned. A wormgear 49 is also fixed to the shaft 46 outwardly from` the cam, and thisworm gear meshes with a worm 50 carried by a shaft 5I. The shaft 5I/isformed of non-conductive material such as brass and is rotatably mountedin bearings 52v carried by the base or housing I. Steel collars 53 aresecured to the shaft 5I by set screws and between these collars ismounted a sleeve 54 which fits loosely upon the shaft. Bushings 55 tloosely about the shaft between the collars and the bearings and thesebus'hings carry gears 56 and 51 which mesh with diametrically opposedportions of a large gear56 carried by the shaft 31 which continuouslyrotates when the scale is in operation and the motor 33 running. Asolenoid 59 ts about the shaft 5I between the annular ange 66 of thebushings 55 and has its coils 6I and 62 separated by the collar 63provided midway the length of the spool 64 of the solenoid, as shown inFigurev '7. When one or the other of the coils is energized, the sleeve54 is magnetized Iand' through the companion collar 53 passes into thecompanion bushing 55 and acts as a clutch to cause rotary motion to belmparted to the shaft 5I from the shaft 31, the direction in which theshaft 5I rotatesbeing controlled according to whether 'rotary' motion istransmitted to the shaft 5I by way of the gear 56 or the gear 51.Rotation of the shaft 5I in one direction swings the quadrant 44 in adirection to effect closing of the gate 38, while rotation of the shaft5I in the opposite direction causes the gate to be opened. Therefore,the speed at which ground or powdered material ilows from the hopper canbe controlled. In

1 case the hopper becomes empty or the material therein should cake tosuch an extent that it ceases to ow from the hopper, the motor should beshut off, and, in order to do so, there has been provided a mercuryswitch 65 mounted upon a rocker bar or bracket 66 which is pivoted atone end, as shown at 61. The vertically extending arm 68 of the bracket66 has its upper end pivoted to one end of a link or -rod S9 whichextends longitudinally of the scale and has its other en d portionloosely received through a lug 16 rising from the top of the quadrantmidway the width thereof. This end portion of the rod is threaded andcarries a nut 1I serving as an abutment adapted to be engaged by the lugand shift the rod longitudinally' to rock the bracket to the positionindicated by dotted lines in Figure 2 and tilt the mercury switch to aposition in which flow of current to the motor will be shut olf..

In view. of the fact that the rod is slidable through the lug, thequadrant may have suilcient movement to eect opening and. closingadjustment of the gate Without shutting oil the motor, but if the hopperbecomes empty, the

the magnetic forcequadrant will vmove to such an extent that the lugwill engage the abutment nut and the switch 63 will be tilted intoposition to open the motor Referring to the -wiring diagram shown in`the current flows through the transformer 15 which reduces the voltageto 9 volts or any other predetermined voltage. From the transformer thecurrent passes through a fuse 16 to a rectifier 11 which changes thecurrent from alternating current to direct current of about six volts.The other lead 18 completes the circuit through the rectifier. From therectifier the current now passes to the mercury tubes 2l by way of theconductor 1S which is split, as shown at Il. Conductors Il and 82 leadfrom the mercury switches to outer ends of the solenoid coils and itwill be readily understood that when either one of .the mercury tubes isengaged by the cooperating magnet 2| or 22 during tilting of the bracketI9 by movement of the arm Il, a circuit will be completed through one ofthe'coils of the solenoid and the gate of the hopper adjusted. When theproper quantity of material Vis flowing from the hopper, the bracket I9will be in its vertical or neutral position and both solenoid coils willbe inactive, but when either too much or not enough material is beingdelivered from the hopper the proper solenoid coil will be energized andmotion will be imparted to the quadrant to open or close the gate. If nomaterial or only a very little is delivered from the hopper, thequadrant will be moved to such an extent that the. mercury tube switchwill be tilted to a4 position in which the motor circuit will be brokenand the motor shut olf. The attendant will then know that a fresh supplymust be placed in the hopper or if he finds that there is plenty ofmaterial in the hopper, he will know that it has become caked tosuch anextent that the agitator cannot feed it through the outlet of thehopper. A condenser coil 83 is provided to dampen or retard theelectrical energy caused by the solenoids and in this manner lessen thestrain on the mercury switchesl There have also been provided signallights 84 and B5 which are connected with the center conductor I6 forthe solenoid by a conductor 81 and other conductor wires 88 lead fromvthe hopper'it flows through the outlet thereof onto the receivingplatform under the hopper. The endless conveyor carries the materialacross the weighing platform longitudinally thereof onto the deliveryplatform and if the material is fed at the proper speed, the scale willbe kept balanced, it being understood that the scale may be set tobalance any predetermined weight of material. The agitator keeps thematerial in the hopper stirred up so that it may be fed through theoutlet at the bottom and delivered onto the receiving platform. When thescale is working properly the gate remains' open a pretermined extent,but if the material should feed too fast or not fast enough, the arm Ilwill be moved by raising or loweringthe weighing platform and 'thebracket I9 tilted towards one side or the other to closethe mercuryswitch 23 or 2l and energize the companion coil of the solenoid. Thevshaft I will then be caused to rotate in the predetermined directionand the quadrant rocked about its pivot to cause opening or closing ofthe gate and a larger or smaller quantity of material permitted to passthrough the outlet of the hopper. The quantity of material fed from thehopper 'will thus be automatically controlled and a predetermined weightmaintained upon the weighing platform. The material is moved along theweighing platform at a steady rate of speed and by timing the operationof the scale or providing a counter and means to operate it each timethe conveyor has made a complete replacement of material upon theweighing platform, as shown in the co-pending application previouslyreferred to, it can be accurately determined how much material haspassed through the scale.

Having thus described the invention, what is claimed as new is:

electric motor for rotating said drive shaft, an

agitator in said hopper actuated by said motor, a gate for the outlet ofsaid hopper movable into and out of closing relation thereto, adjustingmeans for said gate actuated from said drive shaft and including aclutch for controlling directional movement of the gate, electricalmeans for adjusting said clutch including a switch actuated by saidbalancing means, and means for opening the circuit for said motor andshutting off 4the motor when' the gate is opened beyond a predeterminedextent.

2. In a scale, a casing, a hopper over said casing having an outlet inits bottom, a weighing platform in said casing for receiving materialfrom said hopper, balancing means for said platform, a conveyor formoving material along said platform, a drive shaft for said conveyorrotatably mounted transversely through said casing, an electric motorfor rotating said drive shaft, a gate movable into and out of closingrelation to the outlet of said hopper, a rack carried by said gate, agate operating shaft carrying a pinion meshing with the rack and a gear,a quadrant having rack teeth meshing with said gear, a worm gear, a camfor moving said quadrant turning with said worm gear, a transmissionshaft having a worm meshing with said worm gear, a gear carried by saiddrive shaft, gears loose upon said transmission shaft and meshing withopposite side portions of the gear of the drive shaft, a clutch slidablealong said transmission shaft between lts gears, a double coil solenoidabout the transmission shaft and clutch and having a. circuit includinga switch actuated by movements of the balancing means for the rweighingplatform to lselectively energize the coils and move the clutch intoengagement with the gears of the transmission shaft to rotate thetransmission shaft in predetermined directions and actuate the quadrantto open and close the gate, a motor switch, and means actuated by saidquadrant to open the motor switch when the gate is opened beyond apredetermined extent.

3. In a scale, a casing, a hopper over said casing having an outlet atits bottom. a weighing platform in said casing for receiving materialfrom said hopper, balancing means for said platform, a conveyor formoving material along said platform, a drive shaft for said conveyor, amotor for rotating said shaft, a gate for said hopper movable towardsand away from a closed position, actuating means for said gate includinga rotatable shaft and a pivotally mounted quadrant having gearedconnection therewith, al transmission between the drive shaft and saidquadrant for moving the quadrant in a predetermined direction includinga clutch and a double coil solenoid for operating the clutch, and acircuit for the solenoid having a switch for controlling ow of currentthrough the coils and means actuated by the balancing means for theweighing platform for actuating the switch and energizing apredetermined coil to move the quadrant in a direction to open or closethe gate.

4. The structure of claim 3 wherein the transmission shaft .carries apair of loosely mounted gears spaced from each other longitudinallythereof and meshing with opposite side portions of a gear carried by thedrive shaft, a sleeve about the transmission having clutch members atits ends, the loose gears having clutch members for individualengagement by the clutch members of the sleeve when the sleeve isshifted longitudinally upon the transmission shaft, lthe solenoid havingits coils carried by a spodl tting about the sleeve and separated fromeach other by a partitioning collar carried by the spool between thecoils and each disposed about an end portion of the clutchlsleevewhereby the sleeve will be shifted along the transmission shaft toengage the clutch member of a predetermined loose gear when the switchis operated to energize a predetermined coil.

5. The structure of claim 3Awherein the quadrant is pivotallvmounted atits lower end for swinging movement longitudinally of the casing,

an arcuate slot being formed in the upper portion of the quadranttransversely thereof and receiving an end portion of the gate adjusting`tent.

, 6. The structure of claim 3 wherein the switch for Vselectivelyenergizing coils of the solenoid vcomprises a pairof mercury tubes eachinter- Aand away from the tubes, magnets carried by an end portion ofsaid bracket and each moved towards its companion tube during pivotalmovement of the bracket while the otheiUmagnet moves away from itscompanion tube, and a link connecting said bracket with the balancingmeans for the weighing platform and imparting movement to the bracketwhen the balancing means is moved by variation of weight of materialupon the weighing' platform.

7. The structure of claim 3 and a switch for the motor circuit, abracket carrying said motor switch and pivoted to the casing andprovided with an arm, and a rod extending from said arm and looselyengaged through a portion of thequadrant and carrying an adjustableabutment for engagement by the quadrant to exert pull upon the rod andtilt the bracket -to move the switch to a position opening the motorcircuit when the gate is opened beyond a predetermined extent.

8. In a continuous weighing scale, a casing, a weighing platform insaidcasing, balancing means for 'said platform, a hopper having an outletfor delivering material to said platform, a gate for the outlet movabletowardsand away from a closed position, a conveyor for moving materialalong said platform having a drive shaft, a motor for driving saidshaft, a gate adjusting means, means for'transmitting motion from saidshaft to the gate adjusting .means including an electrically actuatedclutchufor controlling directional movement for the gate adjustingmeans, and a switch for selectively energizing the clutch to impartmovement tothe gate in a predetermined direction actuated by thebalancing means for the weighing platform.

9. The structure of claim 8 having a switch provided for the motor, andmeans actuated by -movement of the gate adjusting means for actuatingthe switch to shut -oif the` motor when the gate is opened beyond apredetermined ex- GLEN G. MERCHEN.

